1. Field of the Invention
The present invention relates to an image reading apparatus, a control method of the image reading apparatus, and a storage medium thereof.
2. Description of the Related Art
The conventional image reading apparatus, which reads an image while a document is moved, includes a function to correct an adverse effect caused by an foreign matter (i.e., dust or the like) attached to a document positioning glass. In such image reading apparatus, a document guide plate is read out before the document is read out, and a position and a size of the dust on a platen is calculated to make correction thereof based on information of thus read out document guide plate (see, Japanese Patent Application Laid-open No. 2002-176542). In order to detect white dust which has the same color as the white document guide plate, some image reading apparatus include a detection circuit dedicated to the white dust in addition to a detection circuit for black dust (see, Japanese Patent Application Laid-open No. 2001-86333).
However, in detecting dust having the same color (e.g., a white color) as the document guide plate, the dedicated circuit as disclosed in Japanese Patent Application Laid-open No. 2001-86333 is additionally required. As a result thereof, the apparatus in its entirety requires increased cost.